Academic activity stream

ABSTRACT

A method and computer-readable medium for generating an activity stream is provided. The activity stream includes a ranked set of objects that are presented to one or more users. The ranking of objects is updated to reflect events associated with objects.

FIELD OF THE INVENTION

The present invention relates to methods of organizing objects in anonline learning environment.

BACKGROUND

In general, people are interested in receiving notifications, especiallywhen the notifications are related to items, content, activities, orevents in which the people have shown previous interest or with whichthey are otherwise associated. For example, a person may be interestedin news items associated with a particular keyword or informationassociated with the release of a product. In order to stay up to date onthis information, tools have been developed to allow people to subscribeto email alerts, newsfeeds, and other lists that generally involve agroup of items that are ordered chronologically. For example, a newsfeed may list the most recent news item at the top of a list, while theleast recent news item may be at the bottom.

User activity feeds also tend to be chronologically based. A user of asocial networking site, for example, may be “connected” to hundreds offriends. Status updates made by friends of the user are often displayedin a feed on the user's home page in chronological order. One problemwith seeing feeds in this way is that a feed could have hundreds ofitems, and the most interesting item is very far down the list. Even ifsteps are taken to prune seemingly less interesting items from the list,the most interesting item may still be low on the “interesting” list ifit a large number of items have been added to the interesting list afterthe first item was added to the list. Because the addition of newinteresting items at the top of the list pushes pre-existing interestingitems to lower positions on the list, interesting items eventually getpushed off the list (or at least off the first page of the list that isdisplayed to the user). When this happens, it may be difficult for auser to “catch up” with the popular items from previous days.

The approaches described in this section are approaches that could bepursued, but not necessarily approaches that have been previouslyconceived or pursued. Therefore, unless otherwise indicated, it shouldnot be assumed that any of the approaches described in this sectionqualify as prior art merely by virtue of their inclusion in thissection.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings:

FIG. 1 represents a block diagram of an example system for generating anactivity stream.

FIG. 2 illustrates an example user interface with an activity stream inan embodiment.

FIG. 3 illustrates a computer system upon which an embodiment may beimplemented.

DETAILED DESCRIPTION

In the following description, for the purposes of explanation, numerousspecific details are set forth in order to provide a thoroughunderstanding of the present invention. It will be apparent, however,that the present invention may be practiced without these specificdetails. In other instances, well-known structures and devices are shownin block diagram form in order to avoid unnecessarily obscuring thepresent invention.

General Overview

Techniques are described herein for implementing an activity stream. Anactivity stream includes a ranked list of objects that are associatedwith each other. Within an activity stream, an object (such as anassignment or course syllabus) may have events associated with it. Forexample, a student can “comment” on an assignment. The assignment may belisted as an object within the activity stream, and the comment may beposted under the assignment, in the activity stream, as an event that isassociated with the assignment. A variety of objects can appear in anactivity stream, and each object may have comments and other eventslisted underneath.

The location of an object in the activity stream changes based on eventsthat happen in association with objects in the stream. However, ratherthan simply being pushed further down the list every time a new objectis added to the activity stream, techniques are provided for movingobjects within the activity stream in other ways.

For example, in one embodiment, a book chapter that is currently at alow position in the activity stream rises to the top of the activitystream every time a student comments on the chapter. This dynamicre-ordering of objects in the activity stream is based on the frequencyor recency of events associated with the objects, and/or the popularityof the objects. In one embodiment, users are given the ability todynamically change the way that activity stream objects are ranked, andhow the objects move within the stream in response to events.

In an embodiment, the activity stream is shared, and every user sees thesame ranking of objects in the stream. In another embodiment, theactivity stream is based on user preferences. Other user-information isused to further customize the activity stream to make the activitystream more relevant to the user. Multiple activity streams areavailable to students.

In an embodiment, the activity stream is divided into sections that arebased on a segment of time. For example, the activity stream may bedivided by day. When a day ends, the activity stream section associatedwith the day that has ended is “frozen,” so that no more changes will bemade to that section of the activity stream. This provides a “snapshot”of each day's activity stream for users.

Learning Objects

In some online learning environments, points and other forms of creditare earned by participating in online discussions or by otherwisecontributing to the educational experience of the classroom community.In these scenarios, student contributions may be associated with aparticular object. In the context of online learning environments, theseobjects are sometimes referred to as “learning objects.” Learningobjects may include books, chapters of books, videos and othermultimedia content, audio files, user-generated content, assignments, asyllabus, or any other content that is accessible via a computinginterface such as a personal computer or mobile computing device.

Learning objects may also include instructor notifications or topics ofdiscussion. For example, an instructor may use an instructor interfaceto post a topic as an activity feed object in an attempt to generatediscussion. There are no limits on the textual content of the topic inan embodiment, and the topic may include hyperlinks or embedded media. Atopic may be, for example, a video clip of a debate with associated textthat states: “Which of the debate participants was more persuasive, andwhy?” Students, as well as the instructor, are then able to comment onthe topic. As students respond to the discussion in a thoughtful manner,the instructor may reward the students with points, grades, or otherforms of recognition based on the quality of the student posts.

Events

As used herein, an “event” refers to any occurrence that is associatedwith an object. For example, a comment is a type of event. Comments areassociated with the objects to which the comments are directed. Forexample, when a user comments on a chapter of a book, the comment isassociated with the object that corresponds to that chapter. In anembodiment, the associations between objects and events are implicitlymade by the user, who selects the one or more objects to comment on.Comments are not limited to textual comments. For example, comments mayalso be audio comments, video comments, hyperlinks, computer code, othermultimedia, and any combination thereof.

Events may also include scheduled or unscheduled alerts andnotifications associated with an object. An alert may be associated withan object that represents an assignment for the class. In this case, areminder can be generated to alert students of an upcoming due date.Other notifications may include statistical information that helpsstudents pace their studies. For example, a system event may betriggered when a threshold associated with an object is reached. In anembodiment, when 75% of the students in the class have read a bookchapter, an event is generated and placed in the activity stream inorder to notify all students of the progress. This allows students torecognize the pace of the rest of the class, and modify study habits, ifneeded. A learning management system may be used to feed triggeringinformation to system 100, such as whether or not students in the coursehave completed a particular project or whether they have read aparticular chapter in a book. Since the project and book chapter arelearning objects associated with a class, they are capable of beingassociated with comments and other events.

Events may also be associated with other events. For example, a firststudent may comment on a learning object. A second student may thencomment on the first student's comment. Likewise, a student may postmultimedia content in response to the comment of another student.

The Activity Stream System

FIG. 1 is a block diagram that illustrates a system 100, according to anembodiment. Referring to FIG. 1, input 112 is received by the system 100at an input/output (IO) interface 110. IO interface 110 may be a networkinterface such as an Ethernet-based interface. Input 112 includes eventdata received from users of system 100, such as comments or other userdata 150 about objects 160 stored in storage 130.

IO logic 120 is coupled to IO interface 110. IO logic is configured toparse and distribute incoming data and prepare output 114 for sendingvia 10 interface 110. IO logic 120 may implement one or morecommunications protocols. IO logic 120 is coupled to a storage 130 whichmay be, for example, a database stored on storage media. In theillustrated Objects 150 include learning objects. A “learning object” isany object that is used to facilitate learning. For example, learningobjects may include books, videos, or subsets of each, such as chaptersof books or video clips. Other types of objects, discussed below, arestored in storage 170. User data 160 includes information about users.User data 160 includes user preferences, comments, and otheruser-generated content.

Event data from a user computing device is received as input 112 tosystem 100 via IO interface 110. IO interface 110 provides input 112 tostorage 130, which stores the event data in a table associated with userdata 160. Ranking logic 140 determines a ranking of objects 150 to besent to the user computer based at least in part on the event data. Forexample, event data may be associated with a particular object, causingthe ranking of that object to change. The ranking associated with theobject may be stored in a table associated with objects 150 in storage130. Ranking logic 140 generates an activity stream associated withobjects 150 based on the ranking and provides the ranking to IO logic120. IO logic prepares the activity stream for transmission, andprovides the result as output 114 to IO interface 110, which sendsoutput 114 to the user's computing device.

Activity Stream

FIG. 2 illustrates an example user interface displaying an activitystream in an embodiment. Referring to the activity stream of FIG. 2, atime period indicator 210 indicates a period of time associated with aportion of the activity stream. Time periods may be based on days,weeks, or any other time measurement. Demarcation indicator 240indicates the end of one period of time, and the beginning of another.By segmenting an activity stream based on some criteria, such as time,users of the activity stream are able to see a “snap-shot” of a portionof the activity stream to see what the activity stream looked like atthe end of a particular time period. In one embodiment, because thesegments of past time periods are frozen as snap-shots, the contents ofthose segments remain unchanged even when an event occurs that wouldotherwise cause an object within the frozen segment to be moved toanother portion of the activity stream.

Segmentation criteria other than time may also be used. The activitystream may be segmented by triggers associated with the class. Forexample, a segment may be defined each time a new assignment is providedto the class. As another example, the activity stream may be segmentedby topic, where all objects and events related to a particular topic areadded to the segment for that topic. In such an embodiment, an object orevent that relates to multiple topics may appear multiple times in theactivity stream, once under each of the related topics.

In an embodiment, students are associated with a class, such as Ecology564. The instructor for Ecology 564 may provide a list of available orrequired resources to facilitate learning, such as multimediapresentations, e-books, or assignments. All of these resources may beidentified in system 100 as learning objects that are associated withthe Ecology 564 class, and therefore the Ecology 564 shared activitystream. This particular activity stream is called a shared activitystream because each student in the Ecology 564 class has access to theEcology 564 activity stream, and this activity stream looks the same toeach student in the class.

A student in the class may interact with one of the Ecology 564 learningobjects. For example, the learning object may be the “QuickStart Tour ofthe New Classroom.” As part of the interaction, the student is providedwith the opportunity to generate an event associated with the learningobject. Events may be associated with the learning object in general, orthey may be associated with a portion of the learning object. Forexample, the student may want to discuss a particular section of the“QuickStart Tour of the New Classroom” object called “Post a Comment.”When the student posts a comment, an event indicator such as eventindicators 230-236 is placed in the activity stream in association withan object indicator such as object indicator 220.

If an object indicator associated with an object has not already beenplaced in the activity stream when an event associated with an object isdetected, one will be generated and placed in the activity stream.Likewise, if an event indicator has not been placed in the activitystream in association with the event, one will be created.

Event indicators can be “overloaded.” This means that event indicatorsmay be used to indicate that more than one event has occurred for aparticular learning object. In an embodiment, event indicators aredisplayed with the comment, text, or other content that is associatedwith the event. In another embodiment, event indicators are displayedwith links to the content that is associated with the event. In anembodiment, only overloaded event indicators are displayed with links tothe content for the events that are associated with the overloadedindicator.

In an embodiment, learning objects are collections that are divided intosections, chapters, or distinct parts. Sections, chapters, and parts arealso objects. For example, a collection may be a book, which is dividedinto chapters. In an embodiment, when a student comments on a section ofa collection object, an object indicator for the collection object isdisplayed in the activity stream, and a link associated with the sectionis placed next to an event indicator that is placed in the activitystream in association with the object indicator. The event indicator mayinclude text that identifies the student and/or the section. When thelink is selected, event data, such as comments, text, and multimediacontent associated with the section are shown.

Links or other controls associated with event indicators and objectindicators, when selected by a user, may direct the user's browser to anew web page that includes additional event information, such ascomments about an object. Optionally, controls can cause the event datato be presented in the activity stream without causing the user'sbrowser to change web pages. For example, selecting a link associatedwith an event indicator or an object indicator may invoke an expansionoperation that causes event data to appear below the associated eventindicator. Selecting the control again may invoke a contractionoperation, causing a reversion to the pre-expansion interface.

Different types of activity streams may be generated. A “personalactivity stream” may be generated for a specific user based on thatuser's preferences, associations, and events that are private to thatuser. For example, a personal activity stream may include grades, alertsfor all classes for which the student is enrolled, and learning objectdiscussions for objects the student has already commented on. Emailnotifications and other student messages that are directed to thestudent may also be provided in a personal activity stream. In anembodiment, personal activity streams are not shared with others.

Personal activity streams may be aggregate activity streams, whichinclude content from multiple activity streams. A personal activitystream may include content from several activity streams that thestudent subscribes to or is otherwise associated with. For example, astudent may be enrolled in four classes, and each class may beassociated with a separate activity stream. The student may view asingle activity stream that includes all or some information from theset of streams he is associated with. Thus, information from sharedstreams and personal streams may be aggregated to form an aggregatepersonal activity stream.

Shared activity streams may be used in situations where it is desirablefor all who are associated with the activity stream to see the samecontent. For example, all students that are enrolled in Ecology 564 willsee the same shared activity stream associated with that class in anembodiment.

Ranking Objects in an Activity Stream

Objects are “placed” within a ranked list that is used to generate anactivity stream. As used herein, placing an object at a position in anactivity stream or ranked list means to associate the object with aposition on a list. Likewise, to place an event means to associate anevent. This information is used to generate object indicators and eventindicators, and cause them to be placed in a particular location on auser interface.

One way to place objects on an activity stream is to place each objectat the top of the activity stream the first time that object has anevent associated with it. Using this method, each object is added to thelist once, and has an opportunity to be at the top. However, as otherObjects take their place at the top, the earlier events are “bumped” toa lower position. The position will not change for an object, even ifadditional events are detected in association with that object, unlessanother object is placed at the top of the activity stream.

In online learning environments, it is sometimes desirable to callattention to events that are getting a lot of attention. For example, ifa topic posted by an instructor is generating a lot of discussion amongthe students in the class, a student may wish to join the discussion inorder to seize an opportunity to increase their participation grade orotherwise earn points for the class. Several ranking methods may beimplemented in order to ensure that these “hot topics” are not lost inthe activity stream, and to draw attention to them.

In an embodiment, ranking logic 140 ranks objects according topopularity. Students rank objects according to their interest in theobjects, and the most highly ranked objects are displayed at the top ofthe activity stream. A popularity metric associated with each object isincremented or decremented depending on student feedback. Any method ofranking, such as a star-rating system, can be used (i.e., studentsassign a star value from 1 to 5 to each object). Any other method ofdetermining popularity may be used. The most popular object is thenplaced at the top of the activity stream. Other objects are also rankedaccording to popularity. This is not always the same as putting the mostoverall popular object at the top. In an embodiment, popularity is validover a specific time range, and the popularity metric is reset at theend of each day. The results of each day are “frozen” at the end of theday, and each object has an equal opportunity to become the most popularobject each day.

In an embodiment, ranking logic 140 ranks objects based on recency. Inan academic environment, students may benefit from knowing where theaction is now. Sometimes the most popular item for the day is not themost popular item for the moment. Students seeking to enter a discussionto earn participation credit for a class may benefit from knowing whichobject an event associated with it. Each time an event is generated withrespect to an object, that object is placed at the top of the activitystream, bumping the next-most-recent event down the ranked list. Rankingchanges may be, but need not be, displayed on a user interfaceimmediately. Instead, ranking changes may be applied to a web page at apredetermined time interval, upon the user refreshing the web page, orat any other time. If discussions for a class become stagnant, theranking method may be changed to the popularity-based ranking discussedabove.

It may be the case that the most recent item is not the objectassociated with the highest frequency of events. Sometimes, the objectassociated with the highest frequency of events is the object that ismost consistently capable of generating discussion. Therefore, thenumber of events associated with an object over a particular period oftime may be averaged in order to select the object that mostconsistently attracts events. For example, the object with the mostevents created in association with it within the last hour will beplaced at the top of the activity stream in an embodiment.

Ranking logic 140 uses a round-robin ranking approach is used in anembodiment to swap out topics and other objects to try to increase theirpopularity. For example, each object in a particular stream, in aparticular segment of that activity stream, is placed in the firstposition in the ranked list at least once. Each object in the activitystream, after completing its turn at the first position, is subsequentlyplaced in each position in the ranked list.

Events remain associated with the objects, even as the rankings change.Therefore, event indicators move with their associated objects.

Users may choose which type of ranking method to use. Users may alsospecify a weight to apply to each method, and use multiple methods ofranking. For example, users may indicate that recency should dictatewhich item is at the top of the list, unless frequency for an objectreaches a particular threshold.

Example Method for Generating an Activity Stream

In an embodiment, a ranked list of objects is generated by ranking logic140. In response to detecting a first event associated with a firstobject in the ranked list of objects, ranking logic 140 places the firstobject in a first position in the ranked list. For example, the firstevent may be a comment associated with the first object, and the firstobject may be a book chapter. In response to detecting a second eventassociated with a second object in the ranked list of objects rankinglogic 140 bumps the first object to the second position in the list, andplaces the second object in the first position. In response to anotherevent associated with the first object, the first object is again placedat the first position.

In an embodiment, the ranked list is maintained as multiple segments.Each segment is associated with a time period. For example, each segmentmay be associated with a particular day. After the time periodassociated with a first segment has expired, ranking logic 140 “freezes”the ranking of objects associated with that segment, so that the rankingwithin that segment will no longer change.

In an embodiment, a user profile is maintained in user data 160 forusers of the system, such as students, instructors, faculty, and staff.User profiles include object ranking profile information that indicatesuser preferences for use of ranking techniques. As a user changesranking schemes, ranking logic 140 changes the way in which it generatesactivity streams for that user.

Alternative Embodiments

In an embodiment, instructors or other users of the system 100 may begranted privileges to select objects to “pin” at the top of a particularactivity stream. For example, an instructor may feel that a particulartopic or other learning object is very important. By pinning the objectto the top of the activity stream, the instructor can ensure that thestudents will see the object. An indicator, such as a coloring scheme oricon, may be used to alert students that the object is a “pinned”object.

In an embodiment, students may rank other students in order to customizetheir personal feed and follow students whose interaction they prefer.For example, a first student may not appreciate the tone of discussiongenerated by a second student. The first student may assign a lowranking to the second student, thereby informing ranking logic 140 thatcomments or other events generated by the second student are unwelcomeor should be poorly ranked in the first student's activity stream.

In an embodiment, a threshold associated with events may be set todefine what it takes to trigger the re-ordering of an activity stream.For example, one-word comments may not trigger the re-ordering of anactivity stream.

In an embodiment, events associated with video or audio content may begenerated through interaction with a media player. For example, when astudent selects the play or pause button on a media player on a mediaplayer, events associated with the video content may be generated.

In an embodiment, data generated by ranking logic 140 is fed into alearning management system. The learning management system may use thisdata to recommend content associated with a particular class. Forexample, students may prefer a specific content item, even thoughmultiple content items address the same learning objective.

Hardware Overview

According to one embodiment, the techniques described herein areimplemented by one or more special-purpose computing devices. Thespecial-purpose computing devices may be hard-wired to perform thetechniques, or may include digital electronic devices such as one ormore application-specific integrated circuits (ASICs) or fieldprogrammable gate arrays (FPGAs) that are persistently programmed toperform the techniques, or may include one or more general purposehardware processors programmed to perform the techniques pursuant toprogram instructions in firmware, memory, other storage, or acombination. Such special-purpose computing devices may also combinecustom hard-wired logic, ASICs, or FPGAs with custom programming toaccomplish the techniques. The special-purpose computing devices may bedesktop computer systems, portable computer systems, handheld devices,networking devices or any other device that incorporates hard-wiredand/or program logic to implement the techniques.

For example, FIG. 3 is a block diagram that illustrates a computersystem 300 upon which an embodiment of the invention may be implemented.Computer system 300 includes a bus 302 or other communication mechanismfor communicating information, and a hardware processor 304 coupled withbus 302 for processing information. Hardware processor 304 may be, forexample, a general purpose microprocessor.

Computer system 300 also includes a main memory 306, such as a randomaccess memory (RAM) or other dynamic storage device, coupled to bus 302for storing information and instructions to be executed by processor304. Main memory 306 also may be used for storing temporary variables orother intermediate information during execution of instructions to beexecuted by processor 304. Such instructions, when stored innon-transitory storage media accessible to processor 304, rendercomputer system 300 into a special-purpose machine that is customized toperform the operations specified in the instructions.

Computer system 300 further includes a read only memory (ROM) 308 orother static storage device coupled to bus 302 for storing staticinformation and instructions for processor 304. A storage device 310,such as a magnetic disk or optical disk, is provided and coupled to bus302 for storing information and instructions.

Computer system 300 may be coupled via bus 302 to a display 312, such asa cathode ray tube (CRT), for displaying information to a computer user.An input device 314, including alphanumeric and other keys, is coupledto bus 302 for communicating information and command selections toprocessor 304. Another type of user input device is cursor control 316,such as a mouse, a trackball, or cursor direction keys for communicatingdirection information and command selections to processor 304 and forcontrolling cursor movement on display 312. This input device typicallyhas two degrees of freedom in two axes, a first axis (e.g., x) and asecond axis (e.g., y), that allows the device to specify positions in aplane.

Computer system 300 may implement the techniques described herein usingcustomized hard-wired logic, one or more ASICs or FPGAs, firmware and/orprogram logic which in combination with the computer system causes orprograms computer system 300 to be a special-purpose machine. Accordingto one embodiment, the techniques herein are performed by computersystem 300 in response to processor 304 executing one or more sequencesof one or more instructions contained in main memory 306. Suchinstructions may be read into main memory 306 from another storagemedium, such as storage device 310. Execution of the sequences ofinstructions contained in main memory 306 causes processor 304 toperform the process steps described herein. In alternative embodiments,hard-wired circuitry may be used in place of or in combination withsoftware instructions.

The term “storage media” as used herein refers to any non-transitorymedia that store data and/or instructions that cause a machine tooperation in a specific fashion. Such storage media may comprisenon-volatile media and/or volatile media. Non-volatile media includes,for example, optical or magnetic disks, such as storage device 310.Volatile media includes dynamic memory, such as main memory 306. Commonforms of storage media include, for example, a floppy disk, a flexibledisk, hard disk, solid state drive, magnetic tape, or any other magneticdata storage medium, a CD-ROM, any other optical data storage medium,any physical medium with patterns of holes, a RAM, a PROM, and EPROM, aFLASH-EPROM, NVRAM, any other memory chip or cartridge.

Storage media is distinct from but may be used in conjunction withtransmission media. Transmission media participates in transferringinformation between storage media. For example, transmission mediaincludes coaxial cables, copper wire and fiber optics, including thewires that comprise bus 302. Transmission media can also take the formof acoustic or light waves, such as those generated during radio-waveand infra-red data communications.

Various forms of media may be involved in carrying one or more sequencesof one or more instructions to processor 304 for execution. For example,the instructions may initially be carried on a magnetic disk or solidstate drive of a remote computer. The remote computer can load theinstructions into its dynamic memory and send the instructions over atelephone line using a modem. A modem local to computer system 300 canreceive the data on the telephone line and use an infra-red transmitterto convert the data to an infra-red signal. An infra-red detector canreceive the data carried in the infra-red signal and appropriatecircuitry can place the data on bus 302. Bus 302 carries the data tomain memory 306, from which processor 304 retrieves and executes theinstructions. The instructions received by main memory 306 mayoptionally be stored on storage device 310 either before or afterexecution by processor 304.

Computer system 300 also includes a communication interface 318 coupledto bus 302. Communication interface 318 provides a two-way datacommunication coupling to a network link 320 that is connected to alocal network 322. For example, communication interface 318 may be anintegrated services digital network (ISDN) card, cable modem, satellitemodem, or a modem to provide a data communication connection to acorresponding type of telephone line. As another example, communicationinterface 318 may be a local area network (LAN) card to provide a datacommunication connection to a compatible LAN. Wireless links may also beimplemented. In any such implementation, communication interface 318sends and receives electrical, electromagnetic or optical signals thatcarry digital data streams representing various types of information.

Network link 320 typically provides data communication through one ormore networks to other data devices. For example, network link 320 mayprovide a connection through local network 322 to a host computer 324 orto data equipment operated by an Internet Service Provider (ISP) 326.ISP 326 in turn provides data communication services through the worldwide packet data communication network now commonly referred to as the“Internet” 328. Local network 322 and Internet 328 both use electrical,electromagnetic or optical signals that carry digital data streams. Thesignals through the various networks and the signals on network link 320and through communication interface 318, which carry the digital data toand from computer system 300, are example forms of transmission media.

Computer system 300 can send messages and receive data, includingprogram code, through the network(s), network link 320 and communicationinterface 318. In the Internet example, a server 330 might transmit arequested code for an application program through Internet 328, ISP 326,local network 322 and communication interface 318.

The received code may be executed by processor 304 as it is received,and/or stored in storage device 310, or other non-volatile storage forlater execution.

In the foregoing specification, embodiments of the invention have beendescribed with reference to numerous specific details that may vary fromimplementation to implementation. The specification and drawings are,accordingly, to be regarded in an illustrative rather than a restrictivesense. The sole and exclusive indicator of the scope of the invention,and what is intended by the applicants to be the scope of the invention,is the literal and equivalent scope of the set of claims that issue fromthis application, in the specific form in which such claims issue,including any subsequent correction.

1. A method, comprising: generating a first ranked list of objects foran activity stream; in response to detecting a plurality of eventsassociated with a plurality of objects, placing each of the plurality ofobjects in positions in the first ranked list based on the order inwhich the events occurred; in response to detecting a first eventassociated with a first object in the first ranked list of objects,moving the first object in a first position in the first ranked list,wherein the first event is associated with user activity and the firstobject is associated with a class; in response to detecting a secondevent associated with a second object in the first ranked list ofobjects: moving the first object to a second position in the firstranked list, wherein the second position is lower than the firstposition in the first ranked list; placing the second object in thefirst position in the first ranked list; wherein the second event occursafter the first event; maintaining the ranked list as a plurality ofsegments, wherein each segment is associated with a time period;maintaining a first segment that is associated with a first time period;after detecting the expiration of the first time period: causing theportion of the ranking of objects that is associated with first segmentto remain static; maintaining a second segment that is associated with asecond time period; dynamically updating the portion of the ranking ofobjects that is associated with the second segment in response todetecting a fourth event without updating the portion of the ranking ofobjects that is associated with the first segment; wherein the method isperformed by one or more computing devices.
 2. The method of claim 1,wherein placing the second object in the first position in the rankedlist is performed in response to determining that the second object ismore popular than the first object.
 3. The method of claim 1, whereinplacing the second object in the first position in the ranked list isperformed in response to determining that the second object has a higherfrequency of associated events than the first object.
 4. The method ofclaim 1, wherein moving the first object in the first position in theranked list is performed in response to determining that the firstobject is the object associated with the most recent event.
 5. Themethod of claim 1, further comprising: maintaining, for each of aplurality of users, an object ranking profile, wherein each objectranking profile indicates object ranking preferences for an associateduser of the plurality of users; wherein a first object ranking profileassociated with a first user indicates that the first user prefers aparticular object ranking scheme; wherein moving the first object in thefirst position in the ranked list is performed according to theparticular object ranking scheme.
 6. The method of claim 5, wherein theparticular object ranking scheme is based at least in part on one ormore of: a) the recency of events that associated with objects; b) thefrequency of events associated with objects.
 7. The method of claim 1,wherein: at least one of the plurality of objects is a learning object;and one or more of the events represent comments associated with thelearning object.
 8. The method of claim 1, wherein the activity streamis a shared activity stream that is accessible by a plurality of users.9. The method of claim 1, further comprising: in response to detecting athird event associated with the first object in the ranked list ofobjects, moving the first object to the first position in the rankedlist; presenting the list of objects to a user; wherein the first objectis associated with a child object that is associated with the thirdevent; and presenting the child object in association with the firstobject.
 10. A method, comprising: maintaining a ranked list of objectsfor a first activity stream as a plurality of segments, wherein eachsegment is associated with a time period; maintaining a first segmentthat is associated with a first time period; in response to detecting afirst event associated with a first object in the ranked list ofobjects, changing the position of the first object in the ranked list;after detecting the expiration of the first time period: causing theportion of the ranking of objects that is associated with first segmentto remain static; maintaining a second segment that is associated with asecond time period, wherein the second segment remains dynamic duringthe second time period; wherein both the first segment and the secondsegment are maintained within the first activity stream; wherein themethod is performed by one or more computing devices.
 11. The method ofclaim 10, further comprising: after detecting the expiration of thefirst time period: causing the portion of the ranking of objects that isassociated with first segment to remain static; maintaining a secondsegment that is associated with a second time period.
 12. Acomputer-readable non-transitory storage medium storing instructions,which, when executed by one or more processors, cause the one or moreprocessors to perform: generating a first ranked list of objects for anactivity stream; in response to detecting a plurality of eventsassociated with a plurality of objects, placing each of the plurality ofobjects in positions in the first ranked list based on the order inwhich the events occurred; in response to detecting a first eventassociated with a first object in the first ranked list of objects,moving the first object in a first position in the first ranked list; inresponse to detecting a second event associated with a second object inthe first ranked list of objects: moving the first object in a secondposition in the first ranked list, wherein the second position is lowerthan the first position in the first ranked list; placing the secondobject in the first position in the first ranked list; maintaining theranked list as a plurality of segments, wherein each segment isassociated with a time period; wherein the second event occurs after thefirst event and before the third event; maintaining a first segment thatis associated with a first time period; after detecting the expirationof the first time period: causing the portion of the ranking of objectsthat is associated with first segment to remain static; maintaining asecond segment that is associated with a second time period; dynamicallyupdating the portion of the ranking of objects that is associated withthe second segment in response to detecting a fourth event withoutupdating the portion of the ranking of objects that is associated withthe first segment.
 13. The computer-readable non-transitory storagemedium of claim 12, wherein placing the second object in the firstposition in the ranked list is performed in response to determining thatthe second object is more popular than the first object.
 14. Thecomputer-readable non-transitory storage medium of claim 12, whereinplacing the second object in the first position in the ranked list isperformed in response to determining that the second object has a higherfrequency of associated events than the first object.
 15. Thecomputer-readable non-transitory storage medium of claim 12, whereinmoving the first object in the first position in the ranked list isperformed in response to determining that the first object is the objectassociated with the most recent event.
 16. The computer-readablenon-transitory storage medium of claim 12, wherein the instructionsfurther include instructions for: maintaining, for each of a pluralityof users, an object ranking profile, wherein each object ranking profileindicates object ranking preferences for an associated user of theplurality of users; wherein a first object ranking profile associatedwith a first user indicates that the first user prefers a particularobject ranking scheme; wherein moving the first object in the firstposition in the ranked list is performed according to the particularobject ranking scheme.
 17. The computer-readable non-transitory storagemedium of claim 16, wherein the particular object ranking scheme isbased at least in part on one or more of: a) the recency of events thatassociated with objects; b) the frequency of events associated withobjects.
 18. The computer-readable non-transitory storage medium ofclaim 12, wherein: at least one of the plurality of objects is alearning object; and one or more of the events represent commentsassociated with the learning object.
 19. The computer-readablenon-transitory storage medium of claim 12, wherein the activity streamis a shared activity stream that is accessible by a plurality of users.20. The computer-readable non-transitory storage medium of claim 12,wherein the instructions further include instructions for: in responseto detecting a third event associated with the first object in theranked list of objects, moving the first object to the first position inthe ranked list; presenting the list of objects to a user; wherein thefirst object is associated with a child object that is associated withthe third event; and presenting the child object in association with thefirst object.
 21. A computer-readable non-transitory storage mediumstoring instructions, which, when executed by one or more processors,cause the one or more processors to perform: maintaining a ranked listof objects for a first activity stream as a plurality of segments,wherein each segment is associated with a time period; maintaining afirst segment that is associated with a first time period; in responseto detecting a first event associated with a first object in the rankedlist of objects, changing the position of the first object in the rankedlist; after detecting the expiration of the first time period: causingthe portion of the ranking of objects that is associated with firstsegment to remain static; maintaining a second segment that isassociated with a second time period, wherein the second segment remainsdynamic during the second time period; wherein both the first segmentand the second segment are maintained within the first activity stream.22. The computer-readable non-transitory storage medium of claim 21,wherein the instructions further include instructions for: afterdetecting the expiration of the first time period: causing the portionof the ranking of objects that is associated with first segment toremain static; maintaining a second segment that is associated with asecond time period.